Cranial Nerves

Question 1

What does visceral efferent mean?

Answer 1

Parasympathetic, motor
Innervation of smooth muscle, cardiac muscle and glands

Question 2

What does visceral afferent mean?

Answer 2

Sensory
Sensations from viscera including smell and taste

Question 3

What does somatic efferent mean?

Answer 3

Innervation of skeletal muscles
Motor

Question 4

What does somatic afferent mean?

Answer 4

Sensory
Sensations of vision, touch and pain, hearing and equilibrium

Question 5

CN I name

Answer 5

Olfactory

Question 6

CN function and category?

Answer 6

Sense of smell
VA

Question 7

What happens with lesion to CN I?

Answer 7

Loss of smell (anosmia), ipsilateral

Question 8

CN II name

Answer 8

Optic nerve

Question 9

CN II function and category

Answer 9

Responsible for sight
VA

Question 10

What happens with lesion to CN II?

Answer 10

Lose sight (anopsia, blindness), on the side of the lesion

Question 11

CN III name and category

Answer 11

Oculomotor nerve, SE and VE

Question 12

CN III functions and categories

Answer 12

SE: innervates extraocular muscles to move the eyeball, levator palpebrae superior to keep eyelid lifted
VE: innervates pupillary sphincter and ciliary muscles for pupil dilation and construction

Question 13

CN III what happens with lesion

Answer 13

SE: Lateral strabismus (lateral downward gaze), ptosis (droopy eyelid)
VE: pupil dilates (mydriasis) and loss of pupillary light reflex

Question 14

CN IV name and category

Answer 14

Trochlear nerve, SE

Question 15

CN IV function

Answer 15

SE: innervates super oblique to rotate eye down and towards the middle

Question 16

What happens with lesion to CN IV?

Answer 16

Eye rotates up and outward, diplopia (double vision)

Question 17

CN V name and category

Answer 17

Trigeminal, SA and SE

Question 18

What are the three branches of the trigeminal nerve (CN V)?

Answer 18

Ophthalmic, Maxillary, Mandibular

Question 19

CN V functions, opthalmic branch

Answer 19

SA: sensory information (touch and pain) for forehead, eyes and nose

Question 20

CN V lesion to ophthalmic branch leads to

Answer 20

Ipsilateral loss of touch and pain sensation to forehead

Question 21

CN V functions, maxillary branch

Answer 21

SA: sensory information to midface (touch and pain)

Question 22

CN V lesion to maxillary branch leads to

Answer 22

Ipsilateral loss of sensation of touch and pain for midface

Question 23

CN V functions, mandibular branch

Answer 23

SA: sensation of touch and pain to the lower face, lower dental arch, anterior 2/3 of tongue (no taste), external auditory canal
SE: innervates muscles of chewing, tensor velli palatine (elevate palate), and anterior belly of digastric (upward and anterior movement of larynx)

Question 24

CN V lesion to mandibular branch leads to

Answer 24

Jaw deviating to weak side
Ipsilateral loss of touch and pain sensation for lower face and touch sensation for anterior 2/3 of tongue

Question 25

CN VI name and category

Answer 25

Abducens, SE

Question 26

CN VI function

Answer 26

Innervates lateral rectus to pull eye up and laterally

Question 27

CN VI lesion leads to

Answer 27

Eye deviating medially (medial strabismus)

Question 28

CN VII name and categories

Answer 28

Facial, SE, SA, VE, VA

Question 29

CN VII functions

Answer 29

SE: motor to all muscles of the face for facial expressions SA: sensation to back of pinna VE: innervates sublingual and submandibular salivary glands, nasal mucosa and lacrimal gland, stapedius muscle for acoustic reflex VA: taste sensory info from anterior 2/3 of tongue

Question 30

CN VII lesions lead to

Answer 30

Ipsilateral paralysis of the facial expression muscles Ipsilateral loss of taste from anterior 2/3 of tongue (aguesia) Stapedius paralysis causing acute hearing (hyperacusis)

Question 31

CN VIII name and category

Answer 31

Vestibulocochlear SA

Question 32

CN VIII functions

Answer 32

Hearing and equilibrium

Question 33

CN VIII lesion leads to

Answer 33

Ipsilateral deafness Loss of equilibrium (balance issues, dizziness)

Question 34

CN IX name and category

Answer 34

Glossopharyngeal SA, SE, VA, VE

Question 35

CN IX functions

Answer 35

SE: innervates stylopharyngeus to elevate and widen anterior portion of the pharynx, clear pharynx during swallowing VE: innervates parotid salivary gland to produce saliva (breaks down food) SA: sensation of tactile and pain from posterior 1/3 of tongue, soft palate (gag reflex) VA: taste from posterior 1/3 of tongue

Question 36

CN IX lesion leads to

Answer 36

Ipsilateral loss of taste from posterior 1/3 of tongue Loss of gag reflex (sensory) Dysphagia due to inability to sense bolus in back of mouth to trigger swallow

Question 37

CN X name and category

Answer 37

Vagus, SE, VE, VA

Question 38

CN X functions

Answer 38

SE: innervates pharyngeal constrictors and all palatal muscles except tensor veli palatine (CN V) to push down bolus and intrinsic muscles of larynx for voicing SA: pharyngeal and laryngeal sensation for swallowing VE: innervates heart and viscera to transverse colon VA: sensory to viscera of transverse colon and heart

Question 39

Lesion to CN X leads to

Answer 39

Uvula deviating contralaterally due to ipsilateral soft palate sagging Loss of gag reflex (motor) Unilateral vocal fold paralysis on ipsilateral side; weak and hoarse voice Silent aspiration due to loss of sensation

Question 40

CN XI name and category

Answer 40

Accessory nerve, SE

Question 41

CN XI function

Answer 41

SE: innervates sternocleidomastoid and trapezius

Question 42

CN XI lesion leads to

Answer 42

Difficulty shrugging ipsilateral shoulder Difficulty turning head in contralateral direction

Question 43

CN XII name and category

Answer 43

Hypoglossal nerve, SE

Question 44

CN XII functions

Answer 44

SE: innervates all intrinsic tongue muscles (speech, swallowing), innervates all but one extrinsic tongue muscle (palatoglossus: CN X) for voicing